1. Field
The disclosed embodiments relate to a tool for machining composite material parts and a machining machine comprising such a tool.
2. Brief Description of Related Developments
Composite materials have become very important in many industrial fields. Their field of application, which mainly concerned aeronautics and space, initially, is now expanding and now concerns very different sectors such as the automobile, railway, or entertainment industries (sailboards, etc.).
In the industry of parts for aeronautics, machining is a critical method. It not only helps obtaining accurate dimensions on the manufactured parts, it also makes it possible to obtain complex parts from materials, which would otherwise be difficult to transform.
For composite materials, the trimming operation of a part is directly performed on the final surface treatment, using a machining tool making one or several passes in the thickness of such part, the number of required passes depending on the thickness.
However, it has been noted that the trimming of the composite material part can result in defects in the part, the final product thus obtained not reaching the expected mechanical properties. Such defects, which result from the raising of fibre folds, are also called “spalling”. In the absence of rejection of the part during the quality control, such defects can lead to the breaking of the part during the utilisation.
A more or less rapid wear of such machining tools caused by the absence of checking of the depth of the pass in the thickness of the part, between two passes has also been noted. Now, such premature wear of the tool causes more frequent stoppages of the machining machine and the action of a skilled operator. The costs implied in the changing of the tool, as well as the lost in productivity related to the operator's action duration, are not compatible with the economic obligations of the industry of parts for aeronautics.
Besides, the machining tools of the prior art used for machining composite material parts do not make it possible to make holes or cavities in such parts.
The manufacturing of parts, by cutting in a large dimensioned plate, with such machining tools, thus requires to start from one edge of such plate to reach the first part to be cut. A machine cannot go directly to the starting point of the cutting of the part, since the latter is located by its coordinates in a positioning grid, which is that of the plate.
The cutting of additional material thus implied greatly increases the time required for cutting the parts from the plate and entails a premature wearing of the machining tool.
Finally, the mechanical machining of composite materials also requires more and more advanced cutting tools for greatly increasing the throughput of chips and thus reduce the time required for the trimming operations on a composite material part.